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MG MGF Technical - Fuel consuptiom on a VVC
|I've recently changed my F from a 95 1.8i to a late 98 VVc. I've noticed this new VVc is substantially more thirsty than my other. Can someone with a VVC let me know what they expect to get (mpg wise) during 'normal' urban driving.|
Also is there anything which would cause abnornal fuel consumption, as the car and engine seem to be in great shape.
I have a 97 VVC and get around 32 -34 mpg on a 12 mile urban commute to work. On a motorway or A road run I get much more mpg - depending on how often I go into the VVC zone (over 5,000 rpm) as this seems to make a big difference to the consumption.
I manage to get 32-36 mpg out of mine, and considering work is 10 minutes away, that seems pretty good to me. On a run I have noticed a considerable increase, but I have also noted that with slightly energetic driving (eg upto 4-5K rpm regularly) the mpg only seems to drop to 30-32.
|On my 15 mile cross country route to work recently I've been getting about 38mpg (~400 miles between fills)|
On the recent "fuel free" week, I did 435 on the tank which is about 42mpg. Though I was driving "somewhat more gently" to conserve what I had.
Mine's done 37k miles now in total.
I have all the receipts so I suppose I should key them into a spreadsheet and work it out properly. That would also tell me if there's a difference between when the K&N is fitted and when it isn't (it got taken off prior to garage visits "just in case" there was a problem to solve that it could be blamed for...)
I think it really does depend on how often you use the power....
|I've not accurately measured the consumption yet, but I recently filled it and i've done 60miles, and the tell tale needle has dropped over 1/4 of the guage !!. Looks bad to me.|
A fair point! I have a brandnew 1.8i. I've noticed that the guage takes a very quick drop initially. I haven't worked out my average mpg on my 1.8i, but find it a little worrying!!!!
The sudden drop in your fuel guage can also be down to the shape of the petrol tank.
The information below is taken from the FAQ:
The fuel tank is a saddle tank with the left portion having the sender unit to the fuel gauge, and the pump intake. Since both lobes of the tank contain fuel when at a low level, the fuel in the right lobe cannot be picked up by the pump. Hence, the gauge appears to fall quickly since it only measures part of the contents at 'empty'.
When driving on cross country roads, take a fast right hand bend or roundabout as fast as safety will allow and the contents of the right lobe fall into the left to be picked up by the pump and consequently, the fuel gauge will rise considerably. If driving on a motorway, take an exit ramp and drive quickly around the roundabout over the carriageways and return to the motorway.
If you run out before you notice what the fuel gauge reads, rock the car from side to side to achieve the same result.
|Daniel, thanks for the help, I was aware of the nature of the tank. I've experienced it with my older 1.8i when hammering it around the TT circuit. The other roads on the island don't give you the opportunity to display the characteristics. ;-(|
What concerns me is my older F didn't do this, it used to be arond 100miles at this point !!
I quess the only way will be to measure it,
I take it they didn't change the tank in anyway between 95 and 98. Or theres no difference in the tank between the VVC and 1.8i
|I took the car for a solid run this evening, filled it to the brim, drove it like a bishop (55mph etc) for a couple of hours, did 112miles, and then measured it. Ah to my horror it did 27mpg !!! Obviously this aint right,|
The only modification on this car to my knowledge is that it has an SP Exhaust fitted.
Has anyone got any ideas, on this ???? I don't think my wallet can sustain that sort of optimal consumption.
Additionally my local dealer is about as much use as a chocolate fire guard, the only thing they seem to do successfully is produce invoices !! Thus I'm not to keen taking it to them,
|My 1997 MGF VVC does about 600km per full tank.|
Is this good? Oh yeah I rev moderately
|I drive a Late model '97 VVC. During 'city' driving to and from work on the Gold Coast I get around 550~600km from a tank. (approx 8~9 l/100k or 40mpg) - Although I wouldn't call my drive to work 'real' city driving.. one way trip of 25km and no real stop-start driving..|
On a good run I can get around 700km from a tank (approx 6.7 l/100k or about 50mpg if my calcs are close..)
My driving style dosn't change that much from city to Urban driving.. ie.. It revs to 7250rpm, so that's wat it revs to.. (Not every gear change, but is often in in the range above 5000 rpm.)
Are you sure you don't have a hole in your tank ;-).. I am very happy with the fuel economy of my VVC - My Mini Cooper S uses twice the amount of fuel as my 'F' ! and that is only a 1275cc..
I have a 96 VVC, it has been getting around 30MPG Urban and 36MPG on a run. (and I love to thrash it)
However I had a head gasket failure, and when I got the car back it was doing 20MPG Urban and 30MPG on a run. (It also had an erratic tickover, so I knew there was something wrong)
Anyway to cut a long story short, the fault was caused by the VVC machanism being over advanced which caused it to stick open at lower revs. (it had been put back together incorrectly). This also can happen at a cambelt change.
Once corrected the car has returned to 30MPG Urban and 36MPG on a run.
|As mentioned in the 'General' section, the mpg for my VVC has deteriorated since fitting the K&N. Did about 30+mpg with various driving pre K&N, now does less, towards 25mpg, though I now use it a little more in the 'vroom' range! Haven't really measured the mpg properley since fitting the filter, but the tank empties a lot more quickly!|
The engine is only 7000 miles old and I believe it will improve with age.
Looking forward to 30+ again!
|The consumption of my 96 VVC/K&N was about 34-35 for a long time but it started getting markedly better in recent months up to 38-39. Then I had the HGF (could there be a connection?) and for the last couple of weeks I seem to be down to nearer 30. |
Will the previous economy recover as MEMS maybe recalibrates itself or has my VVC unit been put together wrongly as well. We will see.
|Have hadd two VVCs both give same MPG on very short runs into town only about 32 MPG. Average of all our drives around 36 MPG. Best ever on the Welsh rally was over 43 MPG. We drove from Sussex to near Birmingham, around Wales for a day and half and then, including some full acceleration fun stuff and many hills, back through South Wales and Motorway (high speed) all within one tank, over 43 MPG. They've been very good on fuel, the only car I've owned with better fuel was a diesel , oh and a little 1000cc car I don't want to admit to having owned!|
This thread was discussed between 06/10/2000 and 12/10/2000
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